chore: 拖动元素时的背景图

src/components/BpmnDesign/index.vue

@@ -321,6 +321,13 @@ defineExpose({
 </script>
 
 <style lang="scss" scoped>
+$bg-image: 'data:image/svg+xml;base64,PHN2ZyB3aWR0aD0iNDAiIGhlaWdodD0iNDAiIHhtbG5zPSJodHRwOi8vd3d3LnczLm9yZy8yMDAwL3N2ZyI+PGRlZnM+PHBhdHRlcm4gaWQ9ImEiIHdpZHRoPSI0MCIgaGVpZ2h0PSI0MCIgcGF0dGVyblVuaXRzPSJ1c2VyU3BhY2VPblVzZSI+PHBhdGggZD0iTTAgMTBoNDBNMTAgMHY0ME0wIDIwaDQwTTIwIDB2NDBNMCAzMGg0ME0zMCAwdjQwIiBmaWxsPSJub25lIiBzdHJva2U9IiNlMGUwZTAiIG9wYWNpdHk9Ii4yIi8+PHBhdGggZD0iTTQwIDBIMHY0MCIgZmlsbD0ibm9uZSIgc3Ryb2tlPSIjZTBlMGUwIi8+PC9wYXR0ZXJuPjwvZGVmcz48cmVjdCB3aWR0aD0iMTAwJSIgaGVpZ2h0PSIxMDAlIiBmaWxsPSJ1cmwoI2EpIi8+PC9zdmc+';
+
+/** 从左侧拖动时的背景图 */
+:deep(svg.new-parent) {
+  background: url($bg-image) !important;
+}
+
 .containers {
   height: 100%;
   .app-containers {
@@ -329,7 +336,7 @@ defineExpose({
     .canvas {
       width: 100%;
       height: 100%;
-      background: url('data:image/svg+xml;base64,PHN2ZyB3aWR0aD0iNDAiIGhlaWdodD0iNDAiIHhtbG5zPSJodHRwOi8vd3d3LnczLm9yZy8yMDAwL3N2ZyI+PGRlZnM+PHBhdHRlcm4gaWQ9ImEiIHdpZHRoPSI0MCIgaGVpZ2h0PSI0MCIgcGF0dGVyblVuaXRzPSJ1c2VyU3BhY2VPblVzZSI+PHBhdGggZD0iTTAgMTBoNDBNMTAgMHY0ME0wIDIwaDQwTTIwIDB2NDBNMCAzMGg0ME0zMCAwdjQwIiBmaWxsPSJub25lIiBzdHJva2U9IiNlMGUwZTAiIG9wYWNpdHk9Ii4yIi8+PHBhdGggZD0iTTQwIDBIMHY0MCIgZmlsbD0ibm9uZSIgc3Ryb2tlPSIjZTBlMGUwIi8+PC9wYXR0ZXJuPjwvZGVmcz48cmVjdCB3aWR0aD0iMTAwJSIgaGVpZ2h0PSIxMDAlIiBmaWxsPSJ1cmwoI2EpIi8+PC9zdmc+');
+      background: url($bg-image);
     }
     .el-header {
       height: 35px;